Leak-Preventing Device for a Pump

ABSTRACT

Disclosed is a pump with a shell, an air-pumping device, a cover and a leak-preventing device. The air-pumping device is used to pump air out of the shell and therefore pump liquid into the shell. The cover includes an opening and channel defined therein. The shell is in communication with the exterior via the opening and in communication with the cylinder via the channel as the cover is attached to the shell and the cylinder. The leak-preventing device is connected to the cover. The channel is normally released from the leak-preventing device as the pump is located in an upright position. The channel is blocked by the leak-preventing device as the pump is located in an inverted position.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a pump and, more particularly, to a leak-preventing device for a pump.

2. Related Prior Art

Referring to FIG. 1, a conventional pump 10 is located in an inverted position. The pump 10 includes a shell 11 formed with an upper end 12 and a lower end (not shown). The upper end 12 of the shell 11 is an open end. A check valve (not shown) is located in an aperture (not shown) defined in the lower end of the shell 11. A cylinder 14 is located in the shell 11. A lower end of the cylinder 14 is attached to the lower end of the shell 11. Thus, the space in the cylinder 14 is separated from the space in the shell 11. The check valve is located in the cylinder 14. A flexible piston (not shown) is located in and movable along the cylinder 14. The flexible piston is connected to an end of a rod while a handle is connected to an opposite end of the rod. An annular buoyant 13 is located around and movable along the cylinder 14. A cover 20 is connected to the shell 11 and the cylinder 14. The space in the shell 11 is in communication with the space in cylinder 14 through a channel 22 defined in the cover 20. The cover 20 includes an opening 21 defined therein. A valve 18 is used to close a first end of the channel 22 located in the space in the shell 11. A lever 17 is connected to the valve 18 at an end and connected to another buoyant 16 at an opposite end. The pump is useful in pumping liquid such as used oil 15 out of an oil pan of an engine of for example. In use, the pump is located in an upright position. A plug (not shown) is fit in the opening 21. A flexible pipe (not shown) is inserted through the plug. An end of the flexible pipe is located in the space in the shell 11 while another end of the flexible pipe is located in the used oil 15 contained in the oil pan. The flexible piston is reciprocated in the cylinder 14 to pump air out of the space in the cylinder 14 and hence out of the space in the shell 11. Therefore, some of the used oil 15 is pumped from the oil pan into the space in the shell 11. When the space in the shell 11 is almost full of the used oil 15, the channel 22 is blocked by the valve 18 lifted by the buoyant 16 and the annular buoyant 13 floating on the used oil 15 contained in the pump 10. To pour the used oil from the pump 10, the plug is removed from the opening 21, and the pump 10 is tilted. The used oil is supposed to leave the pump 10 through the opening 21 only. However, there is leak of the used oil from the pump 10 through the channel 22 because the channel 22 is released from the valve 18 moved with the buoyant 16.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide a pump with a leak-preventing device.

To achieve the foregoing objective, the pump includes a shell, an air-pumping device, a cover in addition to the leak-preventing device. The air-pumping device is used to pump air out of the shell and therefore pump liquid into the shell. The cover includes an opening and channel defined therein. The shell is in communication with the exterior via the opening and in communication with the cylinder via the channel as the cover is attached to the shell and the cylinder. The leak-preventing device is connected to the cover. The channel is normally released from the leak-preventing device as the pump is located in an upright position. The channel is blocked by the leak-preventing device as the pump is located in an inverted position.

Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of three embodiments versus the prior art referring to the drawings wherein:

FIG. 1 is a partial, cross-sectional view of a conventional pump in an inverted position;

FIG. 2 is a cross-sectional view of a pump with a leak-preventing device according to the first embodiment of the present invention;

FIG. 3 is an exploded view of the leak-preventing device shown in FIG. 2;

FIG. 4 is a perspective view of the leak-preventing device shown in FIG. 3;

FIG. 5 is a front view of the leak-preventing device shown in FIG. 4;

FIG. 6 is a left side view of the leak-preventing device shown in FIG. 5;

FIG. 7 is a left side view of the leak-preventing device in another position than shown in FIG. 6;

FIG. 8 is a front view of the leak-preventing device in an inverted position relative to the upright position shown in FIG. 5;

FIG. 9 is a perspective view of a lever of a leak-preventing device according to the second embodiment of the present invention; and

FIG. 10 is a perspective view of a lever of a leak-preventing device according to the third embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIGS. 2 through 8, there is shown a pump 30 according to a first embodiment of the present invention. The pump 30 includes a shell 31, a cover 40, an air-pumping device, and a leak-preventing device 60. The shell 31 is formed with a lower end 32 and an upper end 36. The shell 31 includes a base 33 formed at the lower end 32. A check valve 35 is located in an opening (not shown) defined in the lower end 32 of the shell 31. The upper end 36 of the shell 31 is an open end.

The air-pumping device includes a cylinder 50, a handle 51, a rod 52 and a flexible piston 53. The cylinder 50 is located in the shell 31. A lower end of the cylinder 50 is attached to the lower end 32 of the shell 31 by welding for example. Thus, the space in the cylinder 50 is separated from the space in the shell 31. The check valve 35 is located in the cylinder 50. The flexible piston 53 is located in and movable along the cylinder 50. The rod 52 is connected to the flexible piston 53 at an end and connected to the handle 51 at another end.

An annular buoyant 34 is located around and movable along the cylinder 50. The annular buoyant 34 is used with the leak-preventing device 60 in a manner to be described later.

The cover 40 includes a handle 41 formed thereon, an aperture defined therein axially, an opening 42 defined therein longitudinally, a channel 43 defined therein in a radial direction, an upper port defined therein longitudinally, and a lower port defined therein longitudinally. The channel 43 is in communication with the aperture at an end and in communication with both of the upper and lower ports at an opposite end. The cover 40 is connected to the shell 31 and the cylinder 50 so that the space in the shell 31 is in communication with the space in the cylinder 50 via the channel 43. The rod 52 is inserted through the aperture. A relief valve 44 is located in the upper port.

The leak-preventing device 60 is used to close the second end of the channel 43. As clearly shown in FIGS. 3 and 4, the leak-preventing device 60 includes a lever 61, a valve 70 and a weight 80. The lever 61 includes a flat axle 64 extending from a first side near an end, a weight-connecting tab 62 extending from a second side opposite to the first side near an opposite end, and a valve-connecting tab 63 extending from the first side.

The flat axle 64 is located in a recess 45 defined in an extensive portion of the cover 40. A connective plate 46 is attached to the extensive portion of the cover 40 by a screw for example. Thus, the flat axle 64 is retained in the recess 45 by the connective plate 46. Both of the thickness and width of the flat axle 64 are shorter than a diameter of the recess 45 so that the flat axle 64 is rotational in the recess 45, i.e., the lever 61 is pivotally connected to the extensive portion of the cover 40.

The valve 70 includes a reduced section 72 formed thereon. The reduced section 72 of the valve 70 is clipped by the valve-connecting tab 63. The valve 70 is movably located in the lower port as the lever 61 is pivotally connected to the extensive portion of the cover 40.

The weight 80 is connected to the weight-connecting tab 62 by a screw 81 for example. Accordingly, the weight 80 includes a screw hole defined in an end for receiving the screw 81.

The pump 30 is useful in pumping liquid such as used oil out of an oil pan of an engine of for example. Referring to FIGS. 5 and 6, in use, the pump 30 is located in an upright position. The lower port defined in the cover 40 and hence the channel 43 is released from the valve 70. A plug (not shown) is fit in the opening 42. A flexible pipe (not shown) is inserted through the plug. An end of the flexible pipe is located in the space in the shell 31 while another end of the flexible pipe is located in the used oil contained in the oil pan. By operating the handle 51, the flexible piston 53 is reciprocated in the cylinder 50 to pump air out of the space in the cylinder 50 and hence out of the space in the shell 31, i.e., vacuum is created in the space in the shell 31. Therefore, some of the used oil is pumped from the oil pan into the space in the shell 31.

Referring to FIG. 7, as the space in the shell 31 is almost full of the used oil, the lower port defined in the cover 40 and hence the channel 43 is blocked by the valve 70 lifted by the annular buoyant 34 floating on the used oil contained in the space in the shell 31. Thus, no more air can be pumped out of the space in the cylinder 50 and hence out of the space in the shell 31. Therefore, no more used oil can be pumped from the oil pan into the space in the shell 31 by operating the handle 51.

Referring to FIG. 8, to pour the used oil from the pump 30, the plug is removed from the opening 42, and the pump 30 is tilted or inverted. The channel 43 is closed by the valve 70 pressed down by the weight 80. Hence, the used oil leaves the pump 30 through the opening 42 only. There is no leak of the used oil from the pump 30 through the channel 43.

Referring to FIG. 9, a lever 61 according to a second embodiment of the present invention is shown. The second embodiment is like the first embodiment except that the tabs 62 and 63 are formed on the lever 61 so that the axis of the weight 80 and the axis of the valve 70 are located at a same distance from the flat axle 64.

Referring to FIG. 10, a lever 61 according to a third embodiment of the present invention is shown. The third embodiment is identical to the first embodiment except that the tabs 62 and 63 are formed on the lever 61 so that the axis of the weight 80 is located closer to the flat axle 64 than the axis of the valve 70 is.

The present invention has been described via the detailed illustration of the embodiments. Those skilled in the art can derive variations from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims. 

1. A pump including: a shell; an air-pumping device for pumping air out of the shell and therefore pumping liquid into the shell; a cover including an opening and channel defined therein, wherein the shell is in communication with the exterior thereof via the opening and in communication with the air-pumping device via the channel as the cover is attached to the shell and the air-pumping device; and a leak-preventing device connected to the cover, wherein the channel is normally released from the leak-preventing device as the pump is located in an upright position, wherein the channel is blocked by the leak-preventing device as the pump is located in an inverted position.
 2. The pump according to claim 1, wherein the leak-preventing device includes a lever pivotally connected to the cover, a valve connected to the lever for blocking the channel, and a weight connected to the lever for pressing down the valve when the pump is located in the inverted position.
 3. The pump according to claim 2, wherein the lever includes an axle connected to the cover, a valve-connecting tab connected to the valve, and a weight-connecting tab connected to the weight.
 4. The pump according to claim 3, wherein an axis of the valve is located closer to an axis of the axle than an axis of the weight is.
 5. The pump according to claim 3, wherein an axis of the valve and an axis of the weight are located at a same distance from an axis of the axle.
 6. The pump according to claim 3, wherein an axis of the weight is located closer to an axis of the axle than an axis of the valve is.
 7. The pump according to claim 1, wherein the air-pumping device includes a cylinder located in and connected to the shell, a flexible piston movable in the cylinder, a rod connected to the flexible piston, a handle connected to the rod, and a check valve attached to an end of the cylinder.
 8. The pump according to claim 1, further including a buoyant for floating on the liquid to lift the leak-preventing device to block the channel when the shell is almost full of liquid in the upright position.
 9. A pump including: a shell; a cylinder located in and connected to the shell; a flexible piston movable in the cylinder; a rod connected to the flexible piston; a handle connected to the rod; a check valve attached to an end of the cylinder; a buoyant movable along the cylinder; a cover including an opening and channel defined therein, wherein the shell is in communication with the exterior via the opening and in communication with the cylinder via the channel as the cover is attached to the cylinder and the shell; and a leak-preventing device connected to the cover, wherein the channel is normally released from the leak-preventing device as the pump is located in an upright position, wherein the channel is blocked by the leak-preventing device lifted by the buoyant as the shell is almost full of liquid in the upright position, wherein the channel is blocked by the leak-preventing device as the shell is located in an inverted position. 